A plurality of vehicle electronic control devices are connected inside a vehicle and operate in cooperation with each other. Further, a predetermined electronic control device stores a vehicle identification number (VIN code) unique to the vehicle. For example, when a vehicle accident occurs, the electronic control device transmits the vehicle identification number to a public safety answering point (PSAP) which is located outside. For example, Patent Literature 1 relates to the present application.
On the other hand, for example, when a vehicle trouble occurs, and any of electronic control devices which register the vehicle identification number is replaced in a car dealer or the like, a vehicle identification number mismatch may occur, and the electronic control devices may store different identification numbers. In such a case, when the above technique for communicating with PSAP is applied, for example, an incorrect vehicle identification number may be notified to PSAP at the time of a vehicle collision.
Thus, as with the technique described in Patent Literature 1, there is a method in which a majority decision is made between vehicle identification numbers stored in a plurality of electronic control devices, and a majority code is determined to be a correct identification number when the majority code is the same as the majority of the vehicle identification numbers. However, there is no positive proof that the majority code is a correct vehicle identification number. Thus, there is requested a technique for identifying the vehicle identification number as accurately as possible in such a case.